20011601 has 4 divisors (see below), whose sum is σ = 21188772. Its totient is φ = 18834432.

The previous prime is 20011597. The next prime is 20011603. The reversal of 20011601 is 10611002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11397376 + 8614225 = 3376^2 + 2935^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011601 - 2² = 20011597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20011603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 588560 + ... + 588593.

It is an arithmetic number, because the mean of its divisors is an integer number (5297193).

Almost surely, 2^20011601 is an apocalyptic number.

It is an amenable number.

20011601 is a deficient number, since it is larger than the sum of its proper divisors (1177171).

20011601 is a wasteful number, since it uses less digits than its factorization.

20011601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177170.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 20011601 is about 4473.4327981987. The cubic root of 20011601 is about 271.4942347797.

Adding to 20011601 its reverse (10611002), we get a palindrome (30622603).

The spelling of 20011601 in words is "twenty million, eleven thousand, six hundred one".